The problem that I have with fee values is that the purchasing power with Bitcoin is not fixed - a passport created 3 years ago might have needed to burn 100's or 1000's of BTC to claim legitimacy; requiring any application to have some sort of exchange rate lookup as part of the passport application.

I would think it would be better to have some adjusted-purchasing-power token that you can purchase, and then those could be traded on an alt-chain explicitly (kind of like in Anon136's comment above.) Since it lives outside of Bitcoin there is much more flexibility to the rules that can be enforced explicitly to implement contracts and the like with real power, instead of a web-of-trust method of servers checking hashes or polling for fraud notices that live inside the Bitcoin block chain. It is transferable so you don't have to worry (too much) about key compromise destroying the whole reputation.

I posted a thread on this system a few days ago in Repcoin: a decentralized reputation currency.

Unfortunately I think it's not really the right audience in Alternative Cryptocurrencies, and I haven't really gotten any good feedback, even a 'you suck and this system sucks' would be valuable though ...